This invention relates to grinding machines, and more particularly to universal grinding machines of the type having a holding device on which a workpiece head with a chuck is disposed, a grinding wheel secured to a grinding-wheel spindle, and a grinding-wheel spindle holder.
With prior art multi-purpose or universal grinding machines, it has not been possible to carry out drill grinding in addition to cylindrical grinding and surface grinding on the same machine. Thus, the grinding of a milling cutter, for example, has been possible only by using several machines to produce it, which also means that repeated rechucking is necessary. However, rechucking of a workpiece is in any case a potential source of error inasmuch as it may result in the well-known chucking errors, making the sure achievement of high and extremely high precision impossible despite precise tool guidance.
Workpieces are machined on prior art grinding machines with the aid of axial movements of the workpieces. Monitoring of the grinding operations by the operator is made more difficult by the simultaneous rotary and axial motion of the workpiece.
It is an object of this invention to provide a universal grinding machine which allows better monitoring of the grinding operations during cylindrical and drill grinding.
A further object of this invention is to provide a grinding machine with which surface grinding, cylindrical grinding, and/or drill grinding can be carried out on the same workpiece, chucked only once.
To this end, in the universal grinding machine according to the present invention, the grinding-wheel spindle holder is disposed for solely vertical displacement along a guide means, the chuck is rotatable about an axis, and means are provided for positive conversion of the vertical displacement motion of the grinding-wheel spindle holder into rotary motion of the chuck.